A method for second-level controllable synthesis of carbide material under electric field assistance

Abstract

This invention provides a second-level controllable synthesis method for carbide materials under electric field assistance, belonging to the field of carbide synthesis technology. The method includes the following steps: uniformly mixing reactants with a carbonaceous template; placing the resulting mixture in a sealed reaction vessel; applying a direct current to both ends of the mixture to melt the reactants and induce a rapid combustion synthesis reaction with the carbonaceous template to form carbides; and collecting the product after the reaction is complete to obtain the carbide material. This invention utilizes the Marangoni effect to drive the spontaneous spreading of molten reactants on the surface of the carbonaceous template by applying a direct current electric field to induce self-heating of the carbonaceous template, achieving efficient mass transfer, close contact of reactants, and ultra-fast reaction. This method has significant advantages such as second-level reaction rate (1-10 seconds), precise inheritance of morphology and crystal structure, large-scale synthesis, and strong universality, providing a novel technical path for the controllable preparation of carbide materials with different dimensions and morphologies.

Description

Technical Field

[0001] This invention relates to the field of carbide synthesis technology, and in particular to a second-level controllable synthesis method for carbide materials under electric field assistance. Background Technology

[0002] Carbide ceramics, due to their ultra-high hardness, excellent high-temperature stability, outstanding wear and corrosion resistance, and unique semiconductor and optical properties, possess irreplaceable strategic value in aerospace thermal protection systems, nuclear reactor structural materials, high-performance bulletproof armor, semiconductor device substrates, catalyst supports, and new energy and semiconductor fields. The performance of carbide materials is closely related to their microstructure and dimensionality. Carbide materials with different morphologies and dimensions (0-dimensional nanoparticles and microspheres, 1-dimensional fibers, and 2-dimensional nanosheets) exhibit unique mechanical and electrical performance advantages. Therefore, developing preparation techniques that can precisely control the morphology and dimensionality of carbide ceramic materials not only opens new paths for breaking through the limits of material performance in academic research but also provides key material support for high-end engineering applications.

[0003] Currently, the mainstream methods for preparing carbide materials with different morphologies are template-free methods and template methods. Template-free methods include vapor deposition, sol-gel methods, and hydrothermal / solvothermal methods. While these methods can prepare products with specific morphologies, they suffer from drawbacks such as complex equipment, sensitivity to process parameters, low yield, and poor reproducibility. Furthermore, morphology control often relies on complex process optimization, lacking universality. Template methods use a substance with a specific morphology as a template, replicating the template morphology through a reaction. This is currently the mainstream strategy for controllable synthesis of materials with specific morphologies. Template methods are further divided into hard template methods (confined template methods) and soft template methods (open template methods). Hard template methods typically require the pre-synthesis of a template with a specific morphology. Then, the target material is filled or coated within the confined space of the template through chemical vapor deposition or precursor impregnation pyrolysis, and finally, the template is removed by etching or other methods. However, the hard template method is complex, time-consuming, and costly. Furthermore, the template removal process is prone to causing product structural collapse or defects, making large-scale, stable preparation difficult and failing to meet the urgent demand for high-volume, high-quality carbide ceramic materials in high-end applications. The soft template method, on the other hand, directly guides material growth using a carbonaceous template as a framework. Its process is simple, universally applicable, and requires no template removal. However, in the soft template method for synthesizing carbide materials, the synthesis temperature is typically above 1500℃, at which point the reactants are in a molten state. The wettability between the molten material and the solid carbonaceous template is usually poor (contact angle > 90°), limiting the effective spreading of the reactants on the carbonaceous template surface, resulting in slow or even impossible reactions. This is a key scientific problem that the open template method has long struggled to overcome.

[0004] Therefore, improving the wettability between reactants and carbonaceous templates is key to the rapid and precise synthesis of carbide materials with different morphologies using the soft template method. Furthermore, the goal is to develop an ultra-fast, large-scale, and controllable method for synthesizing carbide materials with different morphologies and dimensions to meet the urgent needs of basic scientific research and high-end engineering applications for carbide materials with diverse morphologies. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a second-level controllable synthesis method for carbide materials under electric field assistance. This method applies a DC electric field to induce self-heating of carbonaceous templates with different morphologies, constructing a microreactor with uniformly distributed bulk phase within the reaction system. The temperature difference between the carbonaceous template and the surrounding non-conductive or weakly conductive reactants can be controllably adjusted. The Marangoni effect is utilized to drive the spontaneous spreading of molten reactants on the surface of the carbonaceous template, achieving efficient mass transfer, promoting close contact between the reactants and the carbonaceous template, and facilitating ultra-fast reactions. This enables the second-level, batch, and precise synthesis of carbide materials with different morphologies.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for the second-level controllable synthesis of carbide materials under electric field assistance includes the following steps: S1. Mix the reactants and carbonaceous template evenly to form a mixture; S2. Place the mixture obtained in S1 in a closed reaction vessel, apply a direct current to both ends of the mixture to melt the reactants and react with the carbonaceous template in a rapid combustion synthesis reaction to form carbides; S3. After the reaction is complete, wait for the reactor temperature to cool to room temperature and the pressure to return to normal pressure, take out and collect the product, and obtain the carbide material by simple mechanical grinding.

[0007] Optionally, in step S1, both the reactants and the carbonaceous template are powder materials. The carbonaceous template is selected from one or more of 0D carbon black, 0D carbon spheres, 1D carbon nanotubes, and 2D graphene.

[0008] Optionally, in step S1, the reactants are selected from one or more combinations of silicon powder, boron powder, titanium powder, and calcium powder. The particle size of the reactant powder is 0.1-20µm.

[0009] Optionally, in step S1, the molar ratio of the reactant to the carbonaceous template is (0.5-10):1, preferably (1-5):1.

[0010] Optionally, in step S2, the magnitude of the DC current is 2-10A, and the energizing time is 0.5-10 seconds.

[0011] Optionally, in step S2, the reaction atmosphere is a vacuum of -0.1 to 0 MPa, or nitrogen or argon is introduced to maintain a pressure of 0 to 6 MPa, wherein the nitrogen pressure is preferably 4 to 6 MPa and the argon pressure is preferably 0.5 to 3 MPa.

[0012] Optionally, in step S2, the sealed reaction vessel is a high-pressure reactor, and a crucible is provided inside the reactor to contain the mixture; electrodes are provided on both sides of the crucible and connected to a DC power supply outside the reactor to provide DC current to the mixture.

[0013] Optionally, in step S2, the crucible is made of an insulating material selected from at least one of BN, Si3N4, and Al2O3; and the electrode material is graphite.

[0014] Optionally, in step S3, the morphology of the carbide material is consistent with that of the carbonaceous template.

[0015] The present invention also provides an apparatus for implementing the method, comprising a high-pressure reactor, a crucible, a DC power supply, and electrodes, wherein: The high-pressure reactor is used to provide a high-pressure and single-atmosphere reaction environment; The crucible is located inside the high-pressure reactor and is used to contain the reactants and the carbonaceous template. The electrode is located inside the crucible and includes a positive electrode plate and a negative electrode plate, used to provide heat to the carbonaceous template to promote the reaction. The DC power supply is located outside the high-pressure reactor and is used to provide the continuous current required for the reaction. The electrodes and the DC power supply are connected by wires.

[0016] Compared with the prior art, the present invention has the following significant advantages: 1. Electric field-assisted selective self-heating mechanism, synthesis in seconds.

[0017] Selective self-heating of carbonaceous template materials is achieved through electric field assistance, enabling precise energy release at reaction sites and extremely high energy utilization efficiency. Combustion synthesis reactions can be triggered within seconds, achieving ultra-fast preparation of carbide materials, improving efficiency by several orders of magnitude compared to traditional methods (which take hours to days).

[0018] 2. Built-in microreactor

[0019] Microreactors are built into the reaction system at the microscale, meaning that each carbonaceous template particle and the surrounding adhering reactant powder particles constitute an independent microreaction unit. Numerous microreaction units are simultaneously triggered and react in parallel under the assistance of an electric field, achieving synchronous batch synthesis of the entire material.

[0020] 3. The synergistic effect of template effect and confinement effect enables the precise synthesis of carbides.

[0021] The carbonaceous template maintains structural stability during the reaction, providing a substrate for the heterogeneous nucleation and confined growth of carbides. Within the microreactor, carbides undergo heterogeneous nucleation on the carbonaceous template substrate and grow epitaxially under template induction. Their growth region is strictly confined within the spatial range defined by the carbonaceous template, forming a structural confinement. Ultimately, the carbonaceous template is completely transformed into a carbide product with the same morphology and crystalline state, achieving precise replication and control of the product's microstructure against the morphology and crystalline state of the carbonaceous template.

[0022] 4. Marangoni effect drives the wetting regulation of solid-liquid interfaces

[0023] This invention, for the first time, introduces the Marangoni effect into the field of carbide material synthesis, overcoming the technical bottleneck of poor solid-liquid interface wettability in soft-template methods. It achieves second-level rapid and controllable synthesis of carbide materials with different morphologies using soft-template methods. This method utilizes an electric field to achieve selective self-heating of the carbonaceous template, constructing a controllable temperature difference between the carbonaceous template and surrounding non-conductive or weakly conductive reactants in an open system. Utilizing the Marangoni effect (referring to the spontaneous flow phenomenon of liquids due to differences in surface tension, i.e., surface tension-driven mass transfer), a surface tension difference is generated through the construction of a microscopic temperature gradient within the molten reactants. This drives the spontaneous flow and spreading of the molten reactants, greatly promoting solid-liquid interface wettability, significantly reducing the contact angle, increasing the reaction interface area, and improving the reaction rate. This fundamentally solves the key bottleneck of solid-liquid interface wettability restricting reaction rate, realizing a new and highly efficient synthesis strategy for carbides using open-template methods.

[0024] 5. Highly versatile

[0025] This method is applicable to binary or multi-component systems containing carbon materials and capable of reacting with them, providing a general technical path for the controllable preparation of carbide materials with different morphologies, dimensions, and properties.

[0026] 6. Large-scale preparation

[0027] This method utilizes electric field-assisted technology to achieve selective self-heating of carbonaceous templates, thereby driving parallel combustion synthesis reactions in numerous microreactors. Furthermore, it overcomes the size limitations of traditional methods, enabling single-pass synthesis of gram- to kilogram-scale carbides without complex equipment, reducing synthesis time to the second level. It exhibits significant advantages in low energy consumption and high efficiency, demonstrating excellent industrial scale-up capabilities and promising prospects for large-scale applications. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the reaction equipment for the second-level controllable synthesis method of carbide materials under electric field assistance according to the present invention; Wherein: 1-High-pressure reactor; 2-Crucible; 3-DC power supply; 4-Electrode; 5-Mixed material; Figure 2 These are test images of 0-dimensional SiC nanoparticles in Example 1 of the present invention, where (a) is an XRD pattern and (b) is a SEM image. Figure 3 This is a SEM image of the carbon black raw material in Example 1 of the present invention; Figure 4 These are test images of 1D SiC nanofibers in Example 2 of the present invention, where (a) and (b) are SEM images, and (c) and (d) are EDS images; Figure 5 These are SEM images of the carbon nanotube raw materials used in Examples 2 and 4 of this invention. Figure 6 These are test images of the 2D SiC nanosheets in Example 3 of the present invention, where (a) and (b) are TEM images, and (c) and (d) are EDS images; Figure 7 This is a TEM image of the graphene raw material in Example 3 of the present invention; Figure 8 These are test images of 1D B4C nanofibers in Example 4 of the present invention, where (a) is an XRD pattern and (b) is a SEM pattern. Detailed Implementation

[0030] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0031] This invention provides a second-level controllable synthesis method for carbide materials under electric field assistance, comprising the following steps: S1. Mix the reactants and carbonaceous template evenly to form a mixture; In one embodiment of the present invention, both the reactants and the carbonaceous template are powder materials. The carbonaceous template is selected from one or more of 0D carbon black, 0D carbon spheres, 1D carbon nanotubes, and 2D graphene. In the present invention, the carbonaceous template serves both as a carbon source and as a growth substrate for carbides during the reaction process, ensuring that the morphology of the generated carbides is consistent with that of the carbonaceous template.

[0032] In one embodiment of the present invention, the reactants should be selected from materials whose electrical conductivity differs from that of carbon and which can react with carbon to form carbides. The reactants are selected from one or more combinations of silicon powder, boron powder, titanium powder, and calcium powder, and are used to synthesize carbides such as silicon carbide, boron carbide, titanium carbide, calcium carbide, and titanium carbide. The particle size of the reactant powder is 0.1-20 µm.

[0033] In one embodiment of the present invention, the molar ratio of the reactant to the carbonaceous template is (0.5-10):1, preferably (1-5):1. The above molar ratio is determined by the chemical formula of the target product. To improve the conversion rate of the reactant, the amount of carbonaceous template added can be appropriately increased.

[0034] S2. Place the mixture obtained in S1 in a closed reaction vessel, apply a direct current to both ends of the mixture to melt the reactants and react with the carbonaceous template in a rapid combustion synthesis reaction to form carbides; This invention utilizes the Joule heating generated when an electric current passes through the carbonaceous template to instantly raise the temperature of the carbon material to a high level, while the reactant powder, due to its non-conductive or poor conductivity, remains at a lower temperature. This creates a temperature gradient from the carbonaceous template particle to the reactants within a micro-reactor centered on each carbonaceous template particle. Under the assistance of a continuous electric field, this temperature gradient creates a surface tension difference in the molten reactants, promoting efficient and rapid mass transfer and stimulating a rapid combustion synthesis reaction between the molten reactants and the carbonaceous template particles to form carbide products.

[0035] In one embodiment of the present invention, the magnitude of the DC current is 2-10A, and the energizing time is 0.5-10 seconds. If the energizing current is too large or the energizing time is too long, the reaction will proceed excessively, leading to the decomposition of the carbonaceous template; if the energizing current is too small or the energizing time is too short, it will be difficult to initiate the reaction.

[0036] In one embodiment of the present invention, the reaction atmosphere is a vacuum of -0.1-0 MPa, or nitrogen or argon is introduced to maintain a pressure of 0-6 MPa, wherein the nitrogen pressure is preferably 4-6 MPa and the argon pressure is preferably 0.5-3 MPa.

[0037] In one embodiment of the present invention, the sealed reaction vessel is a high-pressure reactor, and a crucible is provided inside the reactor to contain the mixture; electrodes are provided on both sides of the crucible and connected to a DC power supply outside the reactor to provide DC current to the mixture.

[0038] In one embodiment of the present invention, the crucible is made of an insulating material selected from at least one of BN, Si3N4, and Al2O3; the electrode material is graphite. Neither the crucible nor the electrode material reacts with the mixture or introduces impurities into the product.

[0039] S3. After the reaction is complete, wait for the reactor temperature to cool to room temperature and the pressure to return to normal pressure, take out and collect the product, and after simple mechanical grinding, obtain the carbide material with the morphology of the carbonaceous template.

[0040] The synthetic reactions in the examples and comparative examples were carried out in Figure 1 The reaction is carried out in the apparatus shown. The reaction vessel is a high-pressure reactor 1 with a volume of 6L and a maximum pressure capacity of 15MPa, used to provide a high-pressure and single-atmosphere reaction environment. The reactants (e.g., Si or B) are uniformly mixed with carbonaceous template powder to form a mixture, which is then placed in an insulated BN crucible 2 equipped with graphite electrodes 4 on both sides. A DC power supply 3 is externally located in the high-pressure reactor 1 and connected to the graphite electrodes 4 via wires. The crucible 2 containing the mixture is placed inside the high-pressure reactor 1, and under vacuum or nitrogen / argon conditions, a DC current of 2-10A is applied to the graphite electrodes 4 for 0.5-10 seconds. This allows the current to flow through the carbonaceous powder, forming a pathway. Simultaneously, the carbonaceous powder heats up, initiating a combustion and synthesis reaction with the surrounding reactants, ultimately forming carbide powder.

[0041] Example 1

[0042] Synthesis of 0-dimensional SiC nanoparticles

[0043] Carbon black powder with a particle size of approximately 30 nm and silicon powder with a particle size of approximately 2 µm (molar ratio Si:C = 1) were uniformly mixed to form a Si / C mixture. The Si / C mixture was placed in a sealed reaction vessel, and a 2 A DC current was applied to both ends of the mixture under vacuum (-0.1 MPa) for 5 seconds to induce a rapid combustion synthesis reaction of the Si / C particles, resulting in SiC products. After the reaction was complete, the reactor was allowed to cool to room temperature and the pressure returned to atmospheric pressure before the product was removed and collected. Simple mechanical grinding yielded SiC nanoparticles.

[0044] Figure 2 (a) shows the XRD pattern of the product, indicating that the synthesized product is β-phase SiC. Figure 2 (b) shows the SEM characterization results of the product, which indicates that the product is a spherical nanoparticle with a particle size of approximately 40 nm. Figure 3 Here is a SEM image of the carbon black raw material in Example 1, combined with... Figure 3 and Figure 2(b) It can be seen that the morphology of the product is consistent with that of the initial carbon black particles, and its particle size is comparable to that of the initial carbon black particles.

[0045] Example 2

[0046] Synthesis of 1D SiC nanofibers

[0047] Carbon nanotubes with a diameter of approximately 40 nm and silicon powder with a particle size of approximately 1.6 µm (molar ratio Si:C = 0.9) were uniformly mixed to form a Si / C mixture. The Si / C mixture was placed in a sealed reaction vessel, and a 3 A DC current was applied to both ends of the mixture for 8 seconds under 0.3 MPa argon atmosphere to induce a rapid combustion synthesis reaction between Si and carbon nanotubes, resulting in SiC product. After the reaction was complete, the reactor was cooled to room temperature and the pressure returned to atmospheric pressure. The product was then removed and collected. Simple mechanical grinding yielded SiC nanofibers.

[0048] Figure 4 The images show the SEM and EDS plots of the product. Figure 4 (a) and (b) are SEM images, with (a) showing a higher magnification, revealing that the product is nanofibers with a diameter of approximately 50 nm. Figure 4 Figures (c) and (d) show the EDS characterization results of Figure (b), indicating that the synthesized product is SiC. Figure 5 This is a SEM image of the carbon nanotube raw material used in Example 2. Combined with... Figure 5 and Figure 4 (a) It can be seen that the morphology of the product is consistent with that of the initial carbon nanotubes, and its size is comparable to that of the initial carbon nanotubes.

[0049] Example 3

[0050] Synthesis of 2D SiC Nanosheets

[0051] Graphene nanosheets with a thickness of approximately 100 nm were uniformly mixed with silicon powder (with a particle size of approximately 2.5 µm, molar ratio Si:C = 0.8) to form a Si / C mixture. The Si / C mixture was placed in a sealed reaction vessel, and a 5 A DC current was applied to both ends of the mixture for 6 seconds under 1 MPa nitrogen atmosphere to induce a rapid combustion synthesis reaction between Si and the graphene nanosheets, resulting in the synthesis of SiC products. After the reaction was complete, the reactor was allowed to cool to room temperature and the pressure returned to atmospheric pressure before the product was removed and collected. Simple mechanical grinding yielded the SiC nanosheet product.

[0052] Figure 6 Here are the TEM and EDS images of the product, where Figure 6 (a) and (b) are TEM images, showing that the product is in the form of nanosheets. Figure 7This is a TEM image of the graphene raw material used in Example 3. Combined with... Figure 7 , Figure 6 (a) and Figure 6 (b) It can be seen that the morphology of the product is consistent with the morphology of the initial graphene nanosheets. Figure 6 (c) and (d) are EDS plots of Figure (b), indicating that the synthesized product is SiC.

[0053] Example 4

[0054] Synthesis of 1D B4C nanofibers

[0055] Carbon nanotubes with a diameter of approximately 40 nm and boron powder with a particle size of approximately 3 µm (molar ratio B:C = 3.5) were uniformly mixed to form a B / C mixture. The B / C mixture was placed in a sealed reaction vessel, and an 8 A DC current was applied to both ends of the mixture for 9 seconds under a vacuum of -0.08 MPa, inducing a rapid combustion synthesis reaction between B and the carbon nanotubes to synthesize the B4C product. After the reaction was complete, the reactor temperature was cooled to room temperature and the pressure was restored to atmospheric pressure. The product was then removed and collected. After simple mechanical grinding, the B4C nanofiber product was obtained.

[0056] Figure 8 (a) shows the XRD pattern of the product, indicating that the synthesized product is mainly B4C. Figure 8 Image (b) is a SEM image of the product, showing that it consists of nanofibers with a diameter of approximately 60 nm. Figure 5 and Figure 8 (b) It can be seen that the morphology of the product is consistent with that of the initial carbon nanotubes, and its size is comparable to that of the initial carbon nanotubes.

[0057] Comparative Example 1

[0058] In the synthesis of 0D SiC nanoparticles, carbon black powder with a particle size of approximately 30 nm and silicon powder with a particle size of approximately 2 µm (molar ratio Si:C = 1) are uniformly mixed to form a Si / C mixture. The Si / C mixture is placed in a sealed reaction vessel, and a 30 A DC current is applied to both ends of the mixture under a vacuum of -0.1 MPa for 5 seconds. This induces a rapid combustion synthesis reaction of the Si / C particles, resulting in the SiC product. After the reaction is complete, the reactor temperature is cooled to room temperature and the pressure is restored to atmospheric pressure. The product is then removed and collected. Simple mechanical grinding yields the SiC particle product.

[0059] Unlike Example 1, the test results show that the product generated in Comparative Example 1 is a micron-sized powder with a polyhedral morphology, and its morphology and particle size are not consistent with the initial nano-carbon black particles. This is because, compared with Example 1, the current applied in Comparative Example 1 is too large, resulting in an excessively high temperature in the reaction system, which causes the powder particles to grow significantly and at the same time increases crystallinity.

[0060] Comparative Example 2

[0061] In the synthesis of one-dimensional SiC nanofibers, carbon nanotubes with a diameter of approximately 40 nm and silicon powder with a particle size of approximately 1.6 µm (molar ratio Si:C = 0.9) were uniformly mixed to form a Si / C mixture. The Si / C mixture was placed in a sealed reaction vessel, and a 20 A DC current was applied to both ends of the mixture for 15 seconds under 0.3 MPa argon atmosphere to induce a rapid combustion synthesis reaction between Si and carbon nanotubes, resulting in the SiC product. After the reaction was complete, the reactor was cooled to room temperature and the pressure returned to atmospheric pressure. The product was then removed and collected. Simple mechanical grinding yielded the SiC product.

[0062] Unlike Example 2, the test results show that the products generated in Comparative Example 2 are mostly equiaxed micron-sized particles, and their morphology and particle size are not consistent with the initial carbon nanotubes. This is because, compared with Example 2, the current applied in Comparative Example 2 is larger, and the energizing time is longer, which leads to excessive heat generation of the carbon nanotubes and decomposition, thereby destroying their one-dimensional morphology. The final synthesized product is SiC particles rather than SiC nanofibers.

[0063] Comparative Example 3

[0064] In the synthesis of 2D SiC nanosheets, graphene nanosheets with a thickness of approximately 100 nm and silicon powder with a particle size of approximately 2.5 µm (molar ratio Si:C = 0.8) were uniformly mixed to form a Si / C mixture. The Si / C mixture was placed in a sealed reaction vessel, and a 5 A DC current was applied to both ends of the mixture for 6 seconds under 8 MPa nitrogen atmosphere to induce a rapid combustion synthesis reaction between Si and the graphene nanosheets, resulting in the SiC product. After the reaction was complete, the reactor temperature was cooled to room temperature and the pressure was restored to atmospheric pressure. The product was then removed and collected. Simple mechanical grinding yielded the SiC product.

[0065] Unlike Example 3, the test results showed that the product generated in Comparative Example 3 was mostly micron-sized powder particles, and its morphology and particle size were not consistent with the initial graphene nanosheets. This is because, compared to Example 3, the nitrogen pressure in Comparative Example 3 was higher, which increased the temperature of the reaction system, causing the graphene nanosheets to decompose and thus destroying their two-dimensional morphology. The final product synthesized was SiC particles instead of SiC nanosheets.

[0066] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for the second-level controllable synthesis of carbide materials under electric field assistance, characterized in that, Includes the following steps: S1. Mix the reactants and carbonaceous template evenly to form a mixture. S2. Place the mixture obtained in S1 in a closed reaction vessel, apply a direct current to both ends of the mixture to melt the reactants and react with the carbonaceous template in a rapid combustion synthesis reaction to form carbides; S3. After the reaction is complete, wait for the reactor temperature to cool to room temperature and the pressure to return to normal pressure, then remove and collect the product to obtain the carbide material.

2. The method for second-level controllable synthesis of carbide materials under electric field assistance according to claim 1, characterized in that, In step S1, the carbonaceous template is selected from one or more of 0D carbon black, 0D carbon spheres, 1D carbon nanotubes, and 2D graphene.

3. The method for second-level controllable synthesis of carbide materials under electric field assistance according to claim 2, characterized in that, In step S1, the reactants are selected from one or more combinations of silicon powder, boron powder, titanium powder, and calcium powder, and preferably the particle size of the reactant powder is 0.1-20µm.

4. The method for second-level controllable synthesis of carbide materials under electric field assistance according to claim 3, characterized in that, In step S1, the molar ratio of the reactant to the carbonaceous template is (0.5-10):1, preferably (1-5):

1.

5. The method for second-level controllable synthesis of carbide materials under electric field assistance according to claim 1, characterized in that, In step S2, the magnitude of the DC current is 2-10A, and the energizing time is 0.5-10 seconds.

6. The method for second-level controllable synthesis of carbide materials under electric field assistance according to claim 5, characterized in that, In step S2, the reaction atmosphere is a vacuum of -0.1-0 MPa, or nitrogen or argon is introduced to maintain a pressure of 0-6 MPa, wherein the nitrogen pressure is preferably 4-6 MPa and the argon pressure is preferably 0.5-3 MPa.

7. The method for second-level controllable synthesis of carbide materials under electric field assistance according to claim 5, characterized in that, In step S2, the sealed reaction vessel is a high-pressure reactor, and a crucible is provided inside the reactor to contain the mixture. Electrodes are provided on both sides of the crucible and connected to a DC power supply outside the reactor to provide DC current to the mixture.

8. The method for second-level controllable synthesis of carbide materials under electric field assistance according to claim 7, characterized in that, In step S2, the crucible is made of an insulating material selected from at least one of BN, Si3N4, and Al2O3; the electrode material is graphite.

9. The method for second-level controllable synthesis of carbide materials under electric field assistance according to any one of claims 1 to 7, characterized in that, In step S3, the morphology of the carbide material is consistent with that of the carbonaceous template.

10. An apparatus for implementing the method according to any one of claims 1 to 9, characterized in that, Includes a high-pressure reactor, crucible, DC power supply, and electrodes, wherein: The high-pressure reactor is used to provide a high-pressure and single-atmosphere reaction environment; The crucible is located inside the high-pressure reactor and is used to contain the reactants and the carbonaceous template. The electrode is located inside the crucible and includes a positive electrode plate and a negative electrode plate, used to provide heat to the carbonaceous template to promote the reaction. The DC power supply is located outside the high-pressure reactor and is used to provide the continuous current required for the reaction. The electrodes and the DC power supply are connected by wires.

Images